<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .box{
            margin: 50px auto;
            width: 200px;
            height: 100px;
            /* background: linear-gradient(#fb3 30%,#58a 30%) ;
            background-size: 100% 30px; */
            background: linear-gradient(#fb3 33.3%,#58a 0,#fb3 0,#58a 66.6%,yellow 0) ;
            background-size: 100% 45px;
        }
    </style>
</head>
<body>
    <div class="box">

    </div>
</body>
</html>